They are in the basement.
The silver girl shrugs. "I thought she'd stop being all weird about being a whatever if she was the same as us."
(No touching no touching no touching they'll be mad and if she's doing bad things trying to help Xan they'll hurt Xan)
This will take her by surprise.
By this point, her reflexive response to external things suddenly being done to her is to go still and let it happen.
(Maybe it's good - if the same thing happens to her Xan won't be alone -)
If the fluid gets inside her, passive healing will notice an external substance trying to affect regular operations and start doing something about that.
(Will she inhale fluid?)
She will try to hold her breath.
Passive healing will try to do something about the nanites, but this isn't the kind of thing it's going to be enough for.
Passive healing is not going to be able to keep her conscious with a deconstructed brain.
Meanwhile if anything decides to deconstruct the collar there will be an explosion.
Hannah grunts, but compensates for the sudden release of kinetic energy.
And presumably all the other types.
And so, Hannah sets around rebuilding the girls as transhumans. Reconstructing their bodies on a molecular level. It'll take a few hours, but eh, school holidays.
Well, if she was looking for people who are not very likely to voice complaints about sudden nonconsensual body modification, enslaved mages are a way to go.
(Are they experiencing anything as this happens?)
What's that like?
She was asleep when it started. She can tell something happened but she isn't sure what it was, yet. (They did something to her in her sleep. It will probably mean something but no one has told her what yet so she isn't supposed to do anything.) She feels the adrenaline but doesn't react to it except to ride it through. She tries to look for Jany; she lies still.
Something happened!! They were doing something with Xan (!!) and then they did something to her and it was weird (?!) and now she wants to jump and run around but probably that's bad.
She does not like being stuck in a wet slimy thing! Out out out!
(That is also probably bad but she forgets to think about that. Out!)